Friction false-twisting device

ABSTRACT

One or more groups of three or more endless friction surfaces are supported for rotation and engage and impart a false-twist to a thread engaged thereby as it moves in a path of travel substantially perpendicular to the path of movement of the rotating friction surfaces. The friction surfaces of each group are equally spaced apart and are sequentially engaged by the thread along contact points which lie on a screw-thread line, the pitch and direction of which is determined by the direction of rotation and the positioning of the friction surfaces. The textured yarn produced by the present false-twist device may have torque in either the S or Z direction, depending upon the direction of rotation and arrangement of the friction surfaces. The friction surfaces are disclosed in the form of endless belts, rotating disks having crowned outer circumferential surfaces, and rotating rings having curved inner yarn engaging surfaces.

June 4, 1974 United States Patent 1191 Lorenz 892,791 3/1962 Great Britain......

l2/l967 Great Britain.......................

[ I FRICTION F ALSE-TWISTING DEVICE Inventor: I-Iellmut Lorenz, Remscheid Primary Examiner-DonaldE. Watkins Attorney, Agent, or Firm- Parrott, Bell, Seltzer, Park & ibson m M11 am r no o. .mP u aw n a E a y m n gg a an m mk a n GmA e e n S A l 3 7 Germany [57] ABSTRACT One or more groups of three ormore endless friction [22] Filed: Dec. 4, 1972 [21] Appl. No.1 311,886

surfaces are supported for rotation and engage and impart a false-twist to a thread engaged thereb moves in a path of travel substantiall to'the path of movement of the rota y as it y perpendicular Foreign Application Priority Data Mar. 22, 1972 G'ermany....................

nl a No .m mm a D. n

" faces. The friction surfaces of each gro d apart and are sequentially e d along contact points which 1' ngaged by the References Cited UNITED STATES PATENTS g upon the direction of rotation and arrangement of the friction surfaces. The friction surfaces are disclosed in the form of endless belts, rotating disks'havin 57/77 4 57/77.4 g crowned outer Meili e! 57/77 4 circumferential surfaces, and rotating rings having FOREIGN PATENTS OR APPLICATIONS Curved inner yam engaging Surfaces- 2.923.121 2/l960 3.02 .663 2/1962 Findlow........ 3.103.097 9/19 3 854,780 Great Britain 13 Claims. IODrawing Figures PATENTEH JUN 4:914

- SHEET 1 OF 7 1 FRICTION FALSE-TWISTING DEVICE This invention relates to a friction false-twisting de vice having a number of endless friction surfaces of ball-shapedcross-section rotating in parallel planes and over which a thread is guided, inclined to its direction of movement. A false-twist is imparted to the thread in such a manner that one component of the motion of the friction surface proceeds in the direction of the desired thread-roll motion and the thread embraces each friction surface with a predetermined entry and exit angle. F urther,'the invention involves the proper selection of friction surface rotational direction and the proper positioning of the friction surfaces to produce falsetwisted yarn having torque in either the S or Z direction. The device with which a false-twist is imparted to the moving threads is especially adapted for crimping or curling synthetic thermoplastic yarns or threads.

Devices for curling such thread conventionally consist of a hollow spindlewith a pin extending perpendicular to its axis. The thread is looped around this pin and is guided by the spindle. The spindle is rotated bytangentionally contacting drive belts or rollers-Thereby, the thread is twisted by the spindle against the direction of movement of the thread and it leaves the spindle in i. an untwisted condition (for example see West German Published Specification No. 1,302,699). The demands for increasing thread velocities and decreasing production time have made a constant increase of the rotative speed of the spindle necessary.

Suchfalse-twist spindles have been developed which rotate far above 100,000 revolutions per minute (Austrian Pat. No. 206,104 and West German Published Specification No. 1,302,699). Strength and bearing problems, as well as the difficulty in threading the very small spindle, put a limit to further efforts toward increasing the rotative speed of the spindle. On the other hand, false-twist spindles of this type offer the advantage that its slip in relation to its drive is accurately controllable by adjustment of the contact pressures between the spindle and the driving clement so thatwith such false-twist spindle devices a uniform false-twist and curling can be obtained.

In contrast to this spindle type false-twist device, friction type false-twist devices consist of one or more moving friction surfaces over which a thread is guided in a direction perpendicular or inclined in relation to its direction of movement. In this case, the direction of motion or at least a component of motion of the friction surface extends in the direction of the desired thread-roll motion. With friction false-twist devices many more twists can be imparted to a moving thread than with spindle type false-twist devices since the revolutions of the thread aboutits axis, imparted by the outer forcedirected against the friction surface and pressing the thread onto the friction surface. in the second principle, the friction surface, in the direction of the moving thread, is partially embraced by the thread so that the necessary frictional contact is obtained.

' A fa1se-twist device which operates according to the first principle consists of two disks rotating in the same direction, the axes of which are parallel, their circumferential surfaces are closely spaced so that the thread, moving parallel to the axes, is frictionally engaged between them. The contact point between thread and friction surfaces lies on astraight line connecting the centerlines of the disks (West German Published Specification No. 1,278,903). This type of device has the disadvantage that the thread travel becomes unstable and the point of clamping contact of the thread with the disks continually changes.

In .a further known'type of false-twist device (West German Published Specification No. 1,228,751) the friction producer consists of three shafts, rotatably, arranged on a support plate with their axes extending parallel to each other and passing preferably through the corners of'a triangle having equal sidesyOf the three shafts, at least one is driven and at least three endless belts are looped around the shafts, whereby the three belt runs cross each other between the three shafts to provide the boundary of a thread passage having a triangularly shaped cross section, the inscribed circle of which is matched to the cross section or diameter of the thread to be false-twisted. In thisarrangement, meansis provided for changing the position of the drive belt portions which define the passage, to enlarge or contract the passage to accommodate the diameter of the thread. This friction false-twist device does notapply the necessary torque to the thread for the twisting thereof and does not provide a high and uniform twisting because this belt arrangement does not provide sufficient frictional contact with the very small thread diamete'r.

A false-twist device which employs the second'principal of embracing the friction surfaces consists of a rotating sleeve which, in the direction of the axis, has a bowed inner circumference. The thread is guided through the sleeve in an axial direction'whereby the angle of entry and exit of the thread is between 45 and 90 (West German Published Specification No. 1,205,652 and corresponding US. Pat. No. 2,936,567). The disadvantage, in this case, is that the embracing angle of the thread is theoretically at most I80", but, in reality issmaller. Further, the high degree of tension necessary to carry the thread along with the V smallest possible slip exerts itself in an increased thread tension in the direction of thread movement. Accordfriction surface, are inversely proportional to the very the outer or the inner circumferences of rotating sleeves or rings. For the creation of friction between.

the friction surfaces and the thread, two different principles are used. In the first principle, the friction between friction surfaces and threads is maintained by an ingly, the threadtension against the direction of the thread movement becomes smaller and, as a result, the contact pressure of the thread against the friction sleeve also subsides. Also, the friction velocities adjacent the entrance and exit of the sleeve are larger than in the central area and further the position of the thread is changed in a circumferential direction as it is carried along by the friction surface to produce an ir-,

regular movement of the thread. With this type of falsetwist device, only threads within a certain limited range of deniers, with a restricted characteristic spectrum of sufficiently good quality, may be curled at moderate production speeds. An adjustment to obtain uniform twisting of a number of falsetwisting stations of a ma- 3 chine equipped with this type false-twist devices is, as a result of wear and unavoidable differences in the friction coefficients, possible. only by adjustment of the thread guides to change the angle of embracement of the thread with the sleeve.

Furthermore, friction type-false-twist producers are known which consist of three parallel axes which rotate in the same direction on which are arranged disks which overlap one another. With such a known arrangement, (French Pat. No. 1,203,072 and corre-. sponding U.S.-Pat. No. 2,923,121) each of the three axles are provided with a multitude of disks which are equally spaced in an axial direction and extend between each other in a tight sequence. These disks overlap themselves so that they form an eye or a tight passage which has a width not to exceed the thread diameter as it passes therethrough. The disks are formed cylindrically so that embracement of the thread does not occur along the straight surface of the disks. This type of device does not produce a sufficient and uniform twisting torque to the thread. Also, this twist producer can effect a twisting essentially in only one direction (S or Z rotation). It has'been shown that with a reversed direction of rotation of the disks, the same twisting of the thread can no longer be obtained.

According to another similar arrangement (French Pat. No. 1,202,393 and corresponding U.S. Pat No. 2,939,269), one ofthe axles is provided with only one disk. The two other axles are provided each with two disks above and below the first disk. Each of these disk pairs overlaps itself in such a manner, that a space is formed through which the thread is guided. The single disk or roller serves the purpose to press the thread into the space formed between the disk pairs and is provided with a ball-shaped circumferential surface in the direction of the axis, whereas the other disks are shaped cylindrically, Also, this device can only be used for one twisting direction. Further, the thread is deflected only in one plane and embraces essentially'the middle, ball-shaped roller whereas it essentially merely touches the disk pairs arranged ahead and behind. For this reason, the contact pressure of the thread against the disk is too small to produce a uniform and sufficient twisting movement to the thread.

Finally, a device is known (West German Published Specification No. 1,222,826 and corresponding British Pat. No. 920,658) having three parallel shafts provided with friction disks mounted thereon in which the disks of one-shaft are arranged so close together that only one disk of either of the two other shafts may be positioned between two disks of the first shaft. in this type of false-twister,-different and inpart opposite friction conditions exist from disk to disk. For this reason, the false-twister is not suitable to produce a high twisting since essentially only the disks adjacent the thread exit are effective.

It is an object of the present invention to'provide an A improvement in the known types of false-twist devices whereby a high and uniform false-twisting in a selective S or Z direction may be imparted to synthetic m ultifilament threads having a large range of denier and selected characteristics may be imparted thereto through adjustable friction,m ovem'ent and tensioning conditions. For this purpose, it is preferred thatthe present friction false-twist device include one or more groups each having three or more friction surfaces with the The positions of the friction surfaces are interchangeable and spaced at equal distances in the direction of movement of the thread such that the subsequent contact points provided for the false-twisting of the thread lie on a screw-thread line preselected according to its direction of rotation and that its projection onto a single plane form the comer points of a preferably and essentially equal-sided triangle, rectangle, or polygon.

In this arrangement, the position of at least one friction surface is adjustable in one plane parallel to the remaining friction surfaces. Therefore, the thread passes through a device in a screw line selectable with regards to direction of rotation and pitch angle. In contrast to the known theories, the contact points of the thread with the friction surfaces lie at the corners of the substantially equilateral triangle, rectangle, or polygon which the friction surfaces fomi in the projection to the single plane. This arrangement provides several advantages over the. known types of false-twist devices discussed above. The thread is guided inan inclined direction and adjustable embracing position over the friction surfaces so that the entire effective embracement of the thread can sum up to the desired angle through the series connection of a number of groups of friction surfaces. By this means, it is possible to control to a considerable degree the thread tension before, in and beyond the device according to the technical requirements of the false-twist curling process and especially for influencing the contact pressure of the thread on the friction surfaces and to coordinate the friction and movement conditions between thread and false-twister with the thread characteristics, such as number of individual filaments, denier, and coefficient of friction factor.

Selectively, an S or Z false-twist can be produced. The friction false-twist can be used with various types of thread material having a wide range of thread characteristics, as well as with a wide range of parameters of the curling process. ln this connection, it has been found that one or a number of friction surfaces can be driven with different velocities. v

The friction surfaces can be formed of endless moving belts. Friction surfaces have also proved satisfactory which are formed by rotation surfaces of bodies of rotation rotating in the same direction, 'whereby groups of three or four bodies of rotation are arranged on three or four parallel axles, one behind the other in the direction of the thread movement and in screw-like succession. The distance between at least two axles are adjustable and the positions of the bodies of rotation on at least two of the axles are exchangeable in their sequence in such a manner that the successive points of contact of the thread lie on a preselected screw-thread line in relation to the rotating surfaces and with regard to pitch angle and direction of rotation. In this connection, devices may be provided which permit changing the axial distance between the individual bodies of rotation by a predetermined amount.

The bodies of rotation may consist of round disks provided with ball-shaped outer circumferential surfaces or O-rings having ball-shaped inner surfaces. The

' rotating surfaces may be constructed with different rafriction surfaces being arranged one behind the other.

dii; An arrangement which may be utilized in certain instances includes at least one group of bodies of rotation arranged on axles which can be driven independently of the axles of an additional group and having drive for this additional group of bodies of rotation can beaccomplished by means of a preselected speed ratio from one axle of the so-called main false-twist producer. When a false-twist yarn curling machine is equipped with a multitude of such false-twist stations, two independent drives may also be provided in the machine, one of which drives the so-called main falsetwist producers and the other of which drives the additional group of bodies of rotation. The surfaces of the friction bodies may consistof materials having a high friction value or also of materials having good wear resistance so as steel, coated metals etc. Inasmuch asthe inventive device allows extensive control of the friction condition in the false-twist producer, it is possible that the friction surfaces of one and the same false-twist producer consists of different materials with regards to friction value and wear resistance. In order, with the inventive device, to false-twist a thread in the Z direction, the friction surfaces are arranged such, in the direction of movement of the thread, one behind the other and are rotated in such a direction, that the vectors of movement of the friction surfaces engage the thread in series and rotate in the direction of a lefthand screw.

On the other hand, for the false-twisting of a thread in the S direction, the friction surfaces are arranged such and moved in series in the direction of movement of the thread, that the vectors of movement of the inseries arranged friction surfaces rotate in the direction of a right-hand screw. It is suggested that the friction surfaces are driven in such a manner with diferent velocity and/or parallel staggered in such a way that their component of movement in' the false-twist direction on the friction surface closest to the thread entry, is theoretically established and in the further friction surfaces is larger than the presupposed velocity of rotation of the thread by. the required number of rotations per meter. This process has the advantage that a selfregulating or twist leveling effect occurs at those friction surfaces, in the sense that the entry friction surface provides an additional false-twist producing or falsetwist reducing torque on the thread, depending upon whether the rotation actually imparted to the thread falls below or above the'theo'retical value.

By this means a further means is provided to increase the thread tension in the false-twist producer for intensifying the friction contact between the individual friction surfaces and the thread, without, at the same time, increasing the thread tension in the zone ahead of the false-twist producer, where the threadis normally located in the heating zone in which the false-twisting is heat-set.

The invention will now be described in. connection with the drawings, in'which FIG. 1 is an isometric view of an embodiment of the present friction false-twist'device employing rotating FIG. 2 is an elevational view, with parts in section, of an embodiment of the present friction false-twist device employing rotating disks;

FIG. 3 is a schematic plan view of the friction falsetwist device of FIG. 2, including three axles;

FIG. 4 is a view similar to FIG. 3 but showing a friction false-twist device including four axles;

FIG. 5 is a fragmentary elevation of the lower lefthand side of FIG. 2 with parts in cross-section;

. 6 FIG. 6 is a plan view of the false-twist device illustrated in FIG. 2;

FIG. 7 is an elevational view of an additional or auxiliary false-twist device which is driven from the main friction false-twist device according to FIG. 2;

FIG. 8 is a vertical sectional view through another embodiment of an additional or auxiliary false-twist de- Vice which isdriven from the main friction false-twist device according to FIG. 2;

FIG. 9 is an elevational view with parts in section of another embodiment of the friction false-twist device employing rotating rings or sleeves; and

FIG. 10 is a plan view of the false-twist device according to FIG. 9.

The friction false-twist device shown in FIG. 1 consists of vertically disposed rotating shafts 4, 5 and 6. Each two of these shafts are embraced by a first group of endless belts I, 2 and 3 and a second group of endless belts 11, 12 and 13. Each shaft is provided with two groups of three rotating grooves 14, 15, 16 and l7, 18, 19. The shape of these grooves is matched to the circular or oval cross-section of the belts. The grooves l4,

15, 16 aswell as grooves 17,18, 19 are spaced at equal distances from each other. Shaft 5 is driven by whorl 9 andfriction belt 10. Direction of rotation can be changed through reversal of the drive belt 10. The friction false-twist device is connected to the machine frame by means-of a support plate 7. A guide 20 is positioned at the entrance to the device to direct the thread 8 at an angle to the first belt 1. A thread guide opening 20' is provided at the exit end of the false-twist device to direct the thread 8 at an angle from the last belt 13.

shafts 4 and 5; belt 3 in grooves 16 of shafts 6 and 4;

belt 2 in grooves 15 of shafts S and 6; and'belt l in grooves 14 of shafts 4 and 5.

The shafts 4-6 were driven in a right-hand (clockwise) direction. Under these circumstances, the move- .mentof the projection of the thread as it moves downwardlyinto the bedplate 7, is shown in FIG. 1. The

contact points of the thread with the belts form, in plan view, the comers of a triangle around which the thread travels in a right-hand screw direction, as schematically illustrated in Figure 3.

In one of the tests, the number of shaft revolutions were advanced and the corresponding thread rotations counted. With this arrangement, it was found that a shaft rotation of 3,650'revolutions per minute (rpm) was required in order. to impart twisting of the thread in the order of 3,400 turns per meter. For this test, the diameter of the shaft was 30millimeters in the grooves 14 to 19. The thread tension was 15 grams in advance of the false-twist device and 29 grams behind thefalsetwist device.

With these' values, a thread with uniform curling throughout its length was produced. A knitted piece .wise the same machine adjustment, with the belts arranged as follows: the belts l and 11 in grooves 14 of shafts and 6; the belts 2 and 12 in grooves 15 of shafts 4 and 5; and thebelts 3 and 13 in grooves 16 of shafts 6 and 4. With this arrangement, a twisting of approximately 2,200 turns per meter was obtained. Further, an increased thread tension ratio (thread tension measured ahead and after the device) could be observed. For example, the thread tension in advance of the falsetwist device was 9 grams and behind the false-twist device was 30 to 31 grams. A sufficiently strong curling and a uniformity of the knitted piece produced there- 'with, was not obtained.

With the friction false-twist device according to FIG. 2, the friction surfaces are formed by circular or crowned circumferential surfaces of rotating disks. This false-twist producer consists of three shafts 24, and 26 which rotate in the frame 7. The shafts 24, 25 and 26 are supported in sleeves 30 by means of ball bearings. Shaft 26 is driven through whorl 9 and drive belt It).

The transfer of the rotating motion of shaft 26 to shafts 24 and 25 is accomplished through respective drive belts 37 and 38 and belt pulleys 34, and 36.

false-twister shown in FIGS. 2, 5 and 6. The disks 85, 86, 87, overlap themselves at the center of FIG. 4 and the thread in its travel through the friction falsetwist producer passes along a screw-thread line having a square or rectangular cross-section, shaded in FIG. 4.

From FIGS. 5 and 6, it is obvious that with the falsetwist producer according to FIG. 2, the shaft 24 together with the disks 2land3l mounted thereon is supported for adjustment towards and away from shafts 25, 26. By this means, the overlap triangles, as shown shaded in FIG. 3, can be changed. The frame of the false-twist producer consists of two parts, 7 and 57. Part 7'is solidly supported on the machine frame by screws 74. Bolts 62 and 63 are axially movable in bores of this stationary frame 7 (FIG. 5). At reduced ends 66 and 67 of these bolts, the frame 57 is fastened by means of nuts 68 and 69. The bolts 62 and 63 are provided at their outer ends with collars 70 and 71 and springs 64, 65 through which theysupport themselves on the frame 7. Bolt 62 further carries at its other end a rotatable The rotating disks or thread engaging friction pulleys are provided in' groups with each group including as many pulleys as the false-twist producer has rotating shafts. Accordingly, the first group consists of pulleys 21, 22'and 23' and the second group consists of pulleys 31, 32 and 33. The pulleys of each group follow each other in the direction of the thread and are equally spaced.

The pulleys on each shaft are spaced apart and held cam wheel 59. The cam wheel 59 is rotatably supported between'collar '70 and a ring 72 which is held in position by a screw 73. The cam wheel 59 is provided with a handle 60 and a rotation indicating dial 75 surrounds the cam wheel 59. The outer curved surface of the cam wheel 59 engages a stationary pin 61. Turning of the cam wheel 59 effects a moving to or away of the mov able frame 57 from the stationary frame 7.

The false-twist producer according to FIG. 4, provided with four rotating shafts, may'also be equipped a with an adjusting mechanism of the kind described in against rotation'by sleeve elements 27 so that each pulley may be removed from the shaft. In order to adjust and maintain the distance between the pulleys ofa shaft, sleeve elements 27 of different lengths are inserted on each shaft. For axially fixing the sleeves 27 and the pulleys, washers 29 and screws 28 are used in the upper end of each shaft. Theshaft spacing and the pulley diameters are so arranged that, as; shown in FIG. 3, the first group'of pulleys 2i, 22, 23 and the second group of pulleys 31, 32, 33 each form the shaded overlapping triangle. The double lines in FIG. 3 which extend tangentially of the friction disks or pulleys schematically represent the friction belts of. the false-twist device illustrated in FIG. 1 and form a large equilateral triangle. As the thread passes downwardly and engages the surfaces of the belts or friction disks, it follows a right-hand screw-thread line forming an equilateral triangle in plan view, which is shaded in the opposite direction in FIG. 3.

As shown in FIG. 4, groups of more than three friction surfaces may be inserted at the desired pitch of this screw-thread line. The number of friction surfaces is limited only by the construction and economic expense. FIG. 4 shows a top view of a modified form of friction false-twist device which consists of four rotating shafts 8H, 82, 63 and 84. One or a number of groups of friction disks 85, 86, 87, 86 are mounted on the shafts .and each group consists of four disks corresponding to the number of shafts. The construction of this form of false-twister is substantially the same as the FIGS. 5 and 6. For this, two of the shafts 83 and 84 are supported on the movable frame 57.

In operation of the friction false-twist producer according to FIGS. 2 to 6, the movable frame 57 is moved so far from the stationary frame 7, by turning the cam wheel 59, that the thread, extending parallel to the shafts, finds a passage whereby it can be inserted between the disks. Thereafter, the movable frame 57 is again moved close to the stationary frame until an overlap is formed as shown in FIGS. 3 and 4. The size of the overlap is first experimentallydetermined with consideration of the given thread material, the thread denier and othercharacteristics of the thread, the speed of travel of the thread, the number of turns of twist applied to the thread, the most favorable thread tension for the curling ahead of and behind the false-twist producer, as well as consideration of other parameters. The amount of overlap is fine-adjusted by rotating the cam wheel 59. The setting for a particular set of circumstances can then be determined by noting the rotation indicating dial 75. For producing an S-rotation, the disks are arranged one behind the other in such a manner, that the thread-in its travel through the false-twist producer according to FIG. 2, touches successively each one disk of the shafts 24, 25, 26 or 25, 26, 24 or 26, 24, 25. For the production of a Z-rotation, the disks are rotated in the opposite direction and arranged in reverse order so that the thread, in passing through a false-twist producer according to FIG. 2, touches in sequence one each disk of shafts 24, 26, 25 or 26, 25, 24 or 25, 24, 26.

To produce S-rotation with a false-twist producer according to FIG. 4, the thread, touches successively each one disk of the shafts 81, 82, 83, M52, 83, 84, 81, etc. To produce Z -rotation, the disks are rotated in the 9 opposite direction and arranged in reverse order so that the thread touches successively each one disk of the shafts 84,- 83, 82, 81 or 83, 82, 81, 84, etc.

Example 2 In an experimental arrangement according to Example 1, however, with a false-twist producer according to FIG. 2, a nylon thread 70/34 denier, on the basis of process parameters as-applied in Example I, was produced with uniform curling and, dye absorption. In this case, the rotative speed of the shafts with a-disk diameter of 45 millimeters was 2,600 revolutions per minute; The

thread tension ahead of the false-twist device was grams and behind the false-twist device it was 26 grams.

A change from S-twisting to Z-twisting by merely changing the rotational direction-of the disks, without the rearrangementofthe disks prescribed according to the present invention'and by otherwise the same machine adjustment, produced a twisting of approxiapparatus according to FIGS. 2 or 4. In principal, it is constructed exactly as the friction false-twist device according to FIG. 2 and may be supported on frame 7 of the false-twist producer shown in FIG. 2 by means. of a connecting bracket 47, the lower portion of which is shown in dotted'lines in FIG. 2. The supplementary device is provided with a shaft 48 (FIG. 7) supported in a bearing block 51 on the bracket 47. The shaft 48 is driven through belt pulleys 39 and 49 and drive belt from the shaft 25 of the false-twist producer of FIG. 2. The rotating'motion of shaft 48 is transmitted to shafts 44,45 and 46 of the supplementary deviceby means of driving belts 50, 52, 53 and associated belt pulleys. Arranged on these shafts are a group consisting of three friction disks 41, 42, 43. These disks may, on the basis of a suitable gearratio provided between shafts 25, 48 and 45, be driven by a different, preferably lower circumferential velocity than the-disks of the false-twist producer of FIG. 2. The transmission ratio may be selected such that the component of the disk circumferential speed in the direction of twist corresponds to the theoretical twist to be imparted to the'threa d by the main false-twist device. If now the main false-twist producer of FIG. 2'is adjusted so that it yields the given theoretical rotation, no torque is imparted to the thread through the disks of the supplementary device according to FIG. 7. If, on the other hand, disturbances occur in the falsetwist producer of FIG. 2, for example, through an increase in the slip,- an equalizing torque or twist is provided'to the thread by the disks of the sup-.

plementary device according to FIG. 7. If on the other hand, in case the experimentally determined slip in the false-twist producer of FIG. 2 decreases, through unanticipated fluctuations, a negative torque would be introduced into the thread if it were not for the equalization effect of the supplementary device.

.The supplementary deviceaccording to FIG. 7, on

ducer. By this, not only can the thread tension ahead and behind'the false-twist producer be influenced but also the tension in the falst-twist producer itself and in this way a good contact of the thread can be effected on each individual disk- 1 A further supplementary device, which has the same purpose as the supplementary device according to FIG. 7, is shown in FIG. 8. In FIG. 8, the shaft 24 of the falsetwist producer'of FIG. 2 is shown with the last disk 21 arranged thereon. Shaft 24 is extended somewhat and carries at its upper end a belt pulley and a belt 77. With this arrangement, the rotational movement of shaft 24 is transmitted to a further disk 79 which is freely rotatably fastened on the extension of shaft 26 of the false-twist producer according to .FIG.'2 and is also provided with a belt pulley 78. By means of a selected speed change ratio between belt pulleys76 and 78, the

circumferential speed of disk 79 maybe adjusted different than that of the remaining disks of the false-twist producer according to FIG. 2.

FIGS. 9'and 10show an arrangement of a false-twist device in which the friction surfaces are formed by the curved innersurfaces of rotating rings or sleeves 91, 92, 93. The device includes a frame provided with support arms '94, 95, 96 and a base plate 97 (FIG. 9). Shaft 100 is rotatably supported in the base plate97 by a bearings 101. Shaft 100 is driven by the whorl 9and drive belt 10. Shaft 100 extends upwardly and concentrically through round openings in thesupport arms 94, and 96. Support sleeves 102 and 103 are arranged concentrically to shaft and :aresupported for swinging movement in the arms 94 and 96 and swing arms 98 and 99 are swingably-attached to the sleeves 102, 103.

The rings 91, 92 and 93 are supported by means of ball bearings in the swingable arm 98, the stationaryarm 95 and the swingable arm 99. They are rotated in the same direction by drive belts 104, 105 and 106 are corresponding belt pulleys 107, 108 and 109 from shaft 100. The swinging arms 98 and 99- are urged outwardly from the support arm 95 by respective springs 114, and spring brackets 112, 113 (FIG. 10). The outward swinging motion of the swing arms 98 and 99 is limited by adjusting screws I16, 117 provided with locknuts 118, 119. At their free ends, the swinging arms 98 and 99 are provided with respective handles 120, 121 whereby the swinging arms may be pressed against the force of the springs 114, 115 so that when the other hand, may also be adjusted such, that the overlapping of the friction disks is different fromthe' overlap of the friction disks of the main false-twist prothey are in an alignedposition, a straight passage for the thread is formed throughout the entire false-twist producer. When the swing arms .98 and 99 move outwardly, the thread then is tensioned' and follows a screw-thread line having a triangular cross-section, as shownin FIG. 10. In order to change the twisting direction, the swing arms 98 and 99 swing outwardly in opposite directions from that shown in FIGS. 9 and 10. To

this end, the adjusting screws I17, 118 and springs 114,

115 are rearranged changed.

In the drawings and specification, there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation. I t

As pointed out above, thethread passes through each embodiment of the false-twist device in a screw line which is selectable with regard to both the direction of so that the swing direction is ill rotation and the pitch angle. Also, the type of friction surfaces and their size and spacing may be varied to change the embracing angle of the thread around the friction surfaces, the angle by which the thread is running relative to the axis of the friction surfaces, and the overlap of the friction surfaces.

The following chart illustrates the changes which occur when disks of different size and different frictional surfaces are usd in the device shown in FIGS. 2 and 3, and wherein:

a distance between the axial'centers of the disks b radius of the disks c material on outer surface of disks d =.embracing angle of tread around disks e side length of the triangle with which the disks overlay one another f angle by which the thread is running inclined to the axis of the disks 3 coefficient of friction That which is claimed is:

l. A friction false-twist device adapted to produce crimped and curled thread by false-twisting the thread in either S or Z directions, said device including at least one group of at least three endless frictional surfaces of crowned cross-section, means for rotatably supporting the friction surfaces of each group in equally spaced apart position and for rotation in parallel planes substantially perpendicular to the direction of travel of a thread successively engaging said surfaces, and drive means for selectively rotating said frictional surfaces in clockwise and counterclockwise directions, said friction surfaces being supported for different sequential positioning so that the sequential contact points of said frictional surfaces with the thread lie on a screw-thread line preselected according to the direction of rotation of said frictional surfaces.

2. A device according to claim 1 including means for adjustably supporting at least one of said frictional surfaces for movement toward and away from the remaining frictional surfaces.

3. A device according to claim ll wherein said drive.

tional surfaces are in the form of endless traveling belts.

S. A device according to claim ll wherein said frictional surfaces are in the form of groups of three circu-.

lar bodies of revolution rotating in the same direction, and including three shafts each supporting one of said bodies of revolution of each group, means supporting said shafts for rotation with said bodies of rotation in partially overlapped position, and wherein the bodies of rotation of at least two of said shafts are interchangeable in their sequence.

6. A device according to claim 5 wherein said bodies of rotation consist of round disks having ball-shaped circumferential surfaces. v i

7. A device according to claim 6 wherein the rotational centers of said three shafts are positioned at the corners of an equilateral triangle and are spaced 65 millimeters apart, said round disks including a plastic frictional outer surface and having a radius of 'millimeters to provide sufiicient overlap that the triangular sides of the path of downward travel of the thread are each 1.8 millimeters long. v

8. A device according to claim-6 wherein the rotational centers of said three shafts are positioned at the corners of an equilateral triangle and are spaced 65 millimeters apart, said round disks including a steel frictional outer surface and having a radius of millimeters to provide sufficient overlap that the triangular sides of the path of downward travel of. the thread are each 9.4 millimeters long. r

9. A device according to claim ll wherein said frictional surfaces are in the form of groups of four circular bodies of revolution rotating in the same direction, and includingfour shafts each supporting one of said bodies of revolution of each group, means supporting said shafts for rotation with said bodies of rotation in partially overlapped position, and wherein the bodies of rotation of at least three of said shafts are interchangeable in their sequence.

10. A device according to claim 1 wherein said frictional surfaces are in the form of sleeves havingballshaped in'neryarn engaging surfaces.

11. A device according to claim 1 wherein said frictional surfaces are in the form of groups of circular bodies of revolution rotating in the same direction, and wherein certain of said circular bodies of revolution have different radii.

I 12. A device according to claim 5 including an additional group of bodies of revolution in advance of said recited groups of bodies of revolution, said additional groups of bodies of revolution being supported on shafts which are driven from said shafts supporting said recited groups of bodies of revolution.

' B. A device according to claim 12 including means for driving said additional groups of bodies of revolution at a different speed from said recited groups of bodies of revolution.

Notice of Adverse Decision in Interference In Interference No. 99,763, involving Patent No. 3,813,868, H. Lorenz, FRICTION FALSE-TWISTING DEVICE, final judgment adverse to the patentee was rendered Feb. 7 1980, as to claim 2.

[Oyfiez'al Gazette September 30, 1980.] 

1. A friction false-twist device adapted to produce crimped and curled thread by false-twisting the thread in either S or Z directions, said device including at least one group of at least three endless frictional surfaces of crowned cross-section, means for rotatably supporting the friction surfaces of each group in equally spaced apart position and for rotation in parallel planes substantially perpendicular to the direction of travel of a thread successively engaging said surfaces, and drive means for selectively rotating said frictional surfaces in clockwise and counterclockwise directions, said friction surfaces being supported for different sequential positioning so that the sequential contact points of said frictional surfaces with the thread lie on a screw-thread line preselected according to the direction of rotation of said frictional surfaces.
 2. A device according to claim 1 including means for adjustably supporting at least one of said frictional surfaces for movement toward and away from the remaining frictional surfaces.
 3. A device according to claim 1 wherein said drive means includes means for driving certain of said frictional surfaces at a different speed from the remaining frictional surfaces.
 4. A device according to claim 1 wherein said frictional surfaces are in the form of endless traveling belts.
 5. A device according to claim 1 wherein said frictional surfaces are in the form of groups of three circular bodies of revolution rotating in the same direction, and including three shafts each supporting one of said bodies of revolution of each group, means supporting said shafts for rotation with said bodies of rotation in partially overlapped position, and wherein the bodies of rotation of at least two of said shafts are interchangeable in their sequence.
 6. A device according to claim 5 wherein said bOdies of rotation consist of round disks having ball-shaped circumferential surfaces.
 7. A device according to claim 6 wherein the rotational centers of said three shafts are positioned at the corners of an equilateral triangle and are spaced 65 millimeters apart, said round disks including a plastic frictional outer surface and having a radius of 45 millimeters to provide sufficient overlap that the triangular sides of the path of downward travel of the thread are each 1.8 millimeters long.
 8. A device according to claim 6 wherein the rotational centers of said three shafts are positioned at the corners of an equilateral triangle and are spaced 65 millimeters apart, said round disks including a steel frictional outer surface and having a radius of 50 millimeters to provide sufficient overlap that the triangular sides of the path of downward travel of the thread are each 9.4 millimeters long.
 9. A device according to claim 1 wherein said frictional surfaces are in the form of groups of four circular bodies of revolution rotating in the same direction, and including four shafts each supporting one of said bodies of revolution of each group, means supporting said shafts for rotation with said bodies of rotation in partially overlapped position, and wherein the bodies of rotation of at least three of said shafts are interchangeable in their sequence.
 10. A device according to claim 1 wherein said frictional surfaces are in the form of sleeves having ball-shaped inner yarn engaging surfaces.
 11. A device according to claim 1 wherein said frictional surfaces are in the form of groups of circular bodies of revolution rotating in the same direction, and wherein certain of said circular bodies of revolution have different radii.
 12. A device according to claim 5 including an additional group of bodies of revolution in advance of said recited groups of bodies of revolution, said additional groups of bodies of revolution being supported on shafts which are driven from said shafts supporting said recited groups of bodies of revolution.
 13. A device according to claim 12 including means for driving said additional groups of bodies of revolution at a different speed from said recited groups of bodies of revolution. 